<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .list{
            font-style: 0;
            /* height: 100px; */
        }
        li{
            width: 300px;
            height: 100px;
            font-size: 20px;
            text-align: center;
            float: left;
            list-style: none;
        }
        li:nth-child(1){
            background-color: red;
        } 
        li:nth-child(2){
            background-color: green;
        }
         li:nth-child(3){
            background-color: yellow;
        }
        h2{
            width: 100px;
            height: 150px;
            background-color: black;
        }
        .clear{
            clear: both;
        }
    </style>
</head>
<body>
    <ul class="'list">
        <li>1</li>
        <li>2</li>
        <li>3</li>
        <div class="clear"></div>
    </ul>
    <h2></h2>

</body>
</html>